Abstract: A crane includes a crane main body, a boom, a jib, a boom driving unit, a jib driving unit, a manipulation unit, a drive control unit, a suspension device, a determination unit, and an operation regulating unit. The determination unit determines whether a jib boom angle condition is established or not. The operation regulating unit allows the crane to change a posture between a fall posture and a work posture according to a determination result of the determination unit.

Abstract: A height adjustment assistance device includes an initial state determination part for determining whether a suspended cargo has been lifted from a ground at a start of lifting work, a height detection part for detecting a height of a counterweight from the ground, a storage part for storing an initial height, a calculation part for calculating a target value for correcting the height of the counterweight from the ground based on the initial height and a post-work height, a notification part for notifying an operator of information regarding the target value, and a length adjustment device for adjusting a length of a hanging member by operating in a manner to change the length of the hanging member extending from a tip of a mast to the counterweight.

Abstract: A crane includes a crane main body, a boom, a jib, a boom driving unit, a jib driving unit, a manipulation unit, a drive control unit, a suspension device, a determination unit, and an operation regulating unit. The determination unit determines whether a jib boom angle condition is established or not. The operation regulating unit allows the crane to change a posture between a fall posture and a work posture according to a determination result of the determination unit.

Abstract: A height adjustment assistance device includes an initial state determination part for determining whether a suspended cargo has been lifted from a ground at a start of lifting work, a height detection part for detecting a height of a counterweight from the ground, a storage part for storing an initial height, a calculation part for calculating a target value for correcting the height of the counterweight from the ground based on the initial height and a post-work height, a notification part for notifying an operator of information regarding the target value, and a length adjustment device for adjusting a length of a hanging member by operating in a manner to change the length of the hanging member extending from a tip of a mast to the counterweight.

Abstract: A mobile crane includes a crane main body including a control valve which controls a supply flow rate of hydraulic oil to a main-body driving motor and a pilot-pressure control device which controls a pilot pressure supplied to the control valve. The pilot-pressure control device increases the pilot pressure at a first ratio according to an increase in an operation amount of an operation section when a counterweight carrier is an uncoupled state, increases the pilot pressure at a second ratio lower than the first ratio according to the increase in the operation amount when the counterweight carrier is a coupled state and a grounded state, and increases the pilot pressure at a third ratio higher than the second ratio and equal to or lower than the first ratio according to the increase in the operation amount when the counterweight carrier is the coupled state and an afloat state.

Abstract: A mobile crane includes a counterweight carrier capable of traveling following a movement of a crane main body, the counterweight carrier including a carrier main body on which a counterweight is loaded and a wheel unit attached to the carrier main body and including wheels, a wheel driving device configured to rotate the wheels to thereby cause the counterweight carrier to travel, a loadage detector configured to detect a weight loadage index value, which is an index value of weight of the counterweight loaded on the carrier main body, and a controller configured to cause the wheel driving device to change a driving force of the wheel driving device for rotating the wheels such that the driving force increases as the weight loadage index value detected by the loadage detector increases.

Abstract: A mobile crane includes: a crane main-body having a lower traveling body and an upper swing body; and a counterweight carrier. The counterweight carrier has a wheel, a wheel driving device, and a steering device. At least one of the crane main-body and the counterweight carrier has a controller which causes the steering device to steer the wheel. The controller causes the steering device to steer the wheel by a steering operation which requires a smaller steering amount of the wheel between one steering operation in which the steering device swivels the wheel in one direction to make the orientation of the wheel correspond to the front-back direction of the lower traveling body and another steering operation in which the steering device swivels the wheel in a direction opposite to the one direction to make the orientation of the wheel correspond to the front-back direction.

Abstract: A mobile crane includes a crane main body including a control valve which controls a supply flow rate of hydraulic oil to a main-body driving motor and a pilot-pressure control device which controls a pilot pressure supplied to the control valve. The pilot-pressure control device increases the pilot pressure at a first ratio according to an increase in an operation amount of an operation section when a counterweight carrier is an uncoupled state, increases the pilot pressure at a second ratio lower than the first ratio according to the increase in the operation amount when the counterweight carrier is a coupled state and a grounded state, and increases the pilot pressure at a third ratio higher than the second ratio and equal to or lower than the first ratio according to the increase in the operation amount when the counterweight carrier is the coupled state and an afloat state.

Abstract: A mobile crane includes a counterweight carrier capable of traveling following a movement of a crane main body, the counterweight carrier including a carrier main body on which a counterweight is loaded and a wheel unit attached to the carrier main body and including wheels, a wheel driving device configured to rotate the wheels to thereby cause the counterweight carrier to travel, a loadage detector configured to detect a weight loadage index value, which is an index value of weight of the counterweight loaded on the carrier main body, and a controller configured to cause the wheel driving device to change a driving force of the wheel driving device for rotating the wheels such that the driving force increases as the weight loadage index value detected by the loadage detector increases.

Abstract: A mobile crane includes: a crane main-body having a lower traveling body and an upper swing body; and a counterweight carrier. The counterweight carrier has a wheel, a wheel driving device, and a steering device. At least one of the crane main-body and the counterweight carrier has a controller which causes the steering device to steer the wheel. The controller causes the steering device to steer the wheel by a steering operation which requires a smaller steering amount of the wheel between one steering operation in which the steering device swivels the wheel in one direction to make the orientation of the wheel correspond to the front-back direction of the lower traveling body and another steering operation in which the steering device swivels the wheel in a direction opposite to the one direction to make the orientation of the wheel correspond to the front-back direction.